**Author details**

Lindsay Gates and Jeffrey Indes

Yale University School of Medicine, New Haven CT, USA

### **References**

inclusion of symptomatic and asymptomatic patients. The primary endpoint of any stroke, MI or death at 30-days were similar between CAS and CEA (6.8% versus 7.2%). Upon further examination, patients in the CAS group had a lower rate of MI within 30 days (1.1% versus 2.3%) and patients in the CEA group had a lower 30-day rate of stroke (2.3% versus 4.1%). At one-year follow up quality of life measurements were examined. Investigators found that patients who had strokes reported significantly lower quality of life scores than those who had MI or cranial nerve palsy. After one year, however, these measurements did not show any significant difference. [62,64]The improved outcomes found in the CREST trial may reflect the increased experience of vascular surgeons with endovascular procedures and stent placement as well as the improvement in stents and device designs. This data supports that CAS is not inferior to CEA and both procedures can be safely offered to patients for the treatment of

Current overall recommendations by the Society of Vascular Surgery for intervention in

**1.** For symptomatic patients with stenosis <50% or asymptomatic patients with stenosis <60%

**2.** In patients who have >50% symptomatic lesions or >60% asymptomatic lesions CEA is

3-5 year life expectancy and perioperative stroke/death rates are <3%

**3.** CAS is preferred over CEA in symptomatic patients with >50% stenosis when

the clavicle or distal to the C2 vertebral body

managed with optimal medical therapy

Yale University School of Medicine, New Haven CT, USA

high risk for CEA. [38]

Lindsay Gates and Jeffrey Indes

**Author details**

**b.** Patient has severe uncorrectable CAD, CHF or COPD

**a.** Asymptomatic patients >60% stenosis should be considered for CEA if that have a

**b.** In patients with symptomatic stenosis >50% CEA is preferred, especially if patient is >70, has a long lesion (>15mm), preocclusive stenosis, lipid-rich plaque that can be completely removed, and have not had previous neck operations or radiation

**a.** Patient has a tracheal stoma, scarred and fibrotic tissue from previous ipsilateral surgery or radiation, prior cranial nerve injury, and lesions that extend proximal to

**4.** Asymptomatic patients with >60% stenosis deemed "high risk" for CEA should be

**a.** Insufficient data to recommend CAS for asymptomatic patients that are normal or

carotid artery disease.

preferred to CAS

patients with carotid artery disease are:

12 Carotid Artery Disease - From Bench to Bedside and Beyond

optimal medical therapy is indicated


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**Chapter 2**

**Tissue Characterization**

Masanori Kawasaki, Shinichi Yoshimura and

Additional information is available at the end of the chapter

Carotid plaque vulnerability has been reported to be associated with stroke and other cerebrovascular events [1, 2]. Therefore, tissue characterization of carotid plaques is important to evaluate the risk of cerebrovascular disease and outcome of treatment for carotid arterial stenosis. Stabilization of vulnerable plaques rather than regression of plaque volume is

With respect to the ultrasound technique, ultrasonic tissue characterization of the myocar‐ dium with an integrated backscatter (IBS) analysis was developed, which is capable of providing both conventional two-dimensional echographic (2DE) images and IBS images. In studies of the myocardium, calibrated myocardial IBS was significantly correlated with the volume fraction of interstitial fibrosis [4, 5]. In preliminary *in vitro* studies, IBS values reflected the structural and biochemical composition of atherosclerotic lesion and could differentiate fibrofatty, fatty and calcification of arterial walls [6-8]. However, it is not precise, because IBS values of lipid pool and intimal hyperplasia were similar. Discrimina‐ tion of intimal hyperplasia, fibrous cap and thrombus, and sensitivity and specificity of these measurements were not studied in these papers. Furthermore, extent evaluation of each composition, that is, two-dimensional (2D) tissue structure, in entire plaque has not been examined. Therefore, we measured IBS values in carotid arteries in patients com‐ pared before and immediately after death, and compared these IBS values with their histopathological features. Subsequently, we constructed 2D color-coded maps of arteries

> © 2014 Kawasaki et al.; licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

considered the major contributor to beneficial effects on cerebrovascular events [3].

with plaque to assess visually the arterial tissue characteristics.

**of Carotid Plaques**

http://dx.doi.org/10.5772/57155

Kiyofumi Yamada

**1. Introduction**

**Chapter 2**
